| 摘要 |
drilling equipment, specifically, cone drill bits. SUBSTANCE: drill bit has a valve unit in nipple part, separable packings-nozzles in blow- through conduits and filters preventing water and slime from getting cooling conduits of supports. Valve unit has seat with central hole and sealing coat over all sides fixed immobile on wall of nipple, valve washer with holes and return spring fixing shut-off position of valve unit. Drill bit with simple valve unit reliable in operation provides for sharp increase of sinking per drill bit and for mechanical speed of drilling in water encroached holes. EFFECT: sharp increase of sinking per drill bit. 2 cl, 1 dwg
|
